Improvement on pest resistance of sprayable mulch films by fully utilizing garlic residues

Abstract

Nutrient-rich liquid mulch films containing significant amounts of natural biomass inevitably attract pests, which hinder healthy crop development, despite the advantages of such mulch films in terms of degradability and low cost. To improve the pest resistance of mulch films derived from kitchen waste, we combined garlic residues, kitchen waste, and acrylic monomers to prepare sprayable garlic residue-acrylate liquid mulch films via emulsion polymerization. Garlic residues were fully utilized during the preparation process. The effects of the garlic residue dosage on the viscosity, sprayability, and wicking properties of the emulsions were, as well as the mechanics, water retention, and heat preservation of the garlic residue-acrylate films were studied. Microscopic, spectroscopic, and thermal analysis techniques were employed to characterize and monitor the biodegradability of the optimized garlic residue-acrylate films. The experimental results indicated that the film comprising a 3:7 wt ratio of garlic residues to acrylic monomers exhibited the best overall performance. The prepared garlic residue-acrylate mulch films effectively reduced soil water evaporation (by 2.1–12.3%) and increased soil temperature (by 1.26–3.75%). The optimized garlic residue-acrylate mulch film reached a biodegradation rate of 74.6% and increased the germination rate of pakchoi seeds by 20% relative to bare soil. Meanwhile, it reduced the degree of damage to pakchoi leaves by 11% and the survival rate of Plutella xylostella pests by 30% compared with the nutrient-rich film without garlic residues. The experimental results presented herein demonstrate that the full utilization of garlic residues can improve the performance of sprayable kitchen waste-based mulch films for agricultural applications.